Project Summary. The nearly 3 million US cancer survivors residing in rural areas experience 10% higher cancer mortality compared to their urban counterparts, in part due to poorer cancer treatment adherence. Reasons for rural-urban disparities in cancer treatment adherence are not fully understood. The majority of research to-date has focused on health claims data and small-sample survey data. Moreover, extant data has often neglected the protective and enabling factors that are characteristic of rural communities. A deeper understanding of factors driving cancer treatment non-adherence in rural populations is necessary to design targeted, asset-based interventions to reduce rural health disparities and improve outcomes. The premise of the proposed research is that multi-level factors contribute to the observed rural-urban differences in cancer treatment adherence and outcomes, including sociodemographic inequities and diminished access to healthcare, psychosocial services, and technological advances. Rural cultural factors serve as barriers and facilitators to treatment adherence and may be positively impacted by digitally-mediated interventions. The purpose of the proposed research is to elucidate social and behavioral factors encompassing rural culture as it relates to oncology treatment non-adherence and delineate factors amenable to targeted, tailored approaches to improve rural oncology outcomes. These goals will be accomplished by a rigorous mixed methods approach utilizing population-based surveys, semi-structured interviews, and ecological momentary assessment, supported by community engagement across study phases to capitalize on strengths of rural culture while minimizing barriers. A highly qualified multi-disciplinary team has been assembled to support my research and training goals in mixed methodology and rural community engagement. The proposed F99/K00 application targets the NCI's emerging priority of rural cancer control and aligns with current NCI funding initiatives in rural oncology and implementation science. Completion of this unique pre to post-doctoral fellowship transition award will provide me with the skills and experience necessary to be a highly trained cancer control researcher with specific expertise in 1) rural populations, 2) health disparities, 3) patterns of care, and 4) care coordination and delivery - four of the seven NCI Division of Cancer Control and Population Sciences areas of research emphasis, thus expertly preparing me to advance the field of rural cancer control through the development of innovative and scalable interventions addressing the self-management support needs of this underserved population.